[ofa-general] Some confusion about DOR algorithm

[Jordan]

I have some confusion about the DOR algorithm , in this algorithm , It
chooses the outport throuth a "for" iteration :for (i = start_from; i <
start_from + num_ports; i++).  So the  small port_num will be choosed
firstly.
But not always the small port_num connects the X-dimension or Y-dimension.In
other words , using this method we can't always conform the DOR rule.
By the way , in the specification, it says " Paths are grown from a
destination back to a source using the lowest dimension (port) of available
paths at each step. ". Maybe ,the lowest port connect to the X-dimension in
one switch, but it connects to the Y-dimension in another switch. So when
routing the package from A to B, the dimension may be X -Y- Y- X- X- Y, not
X-X-X- Y-Y-Y . This will   break the DOR rule.

Can anybody explain this situation?
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openfabrics.org/pipermail/general/attachments/20090623/84c5506f/attachment.html>